1. Field of the Invention
This invention relates in general to the field of self contained underwater breathing apparatus (SCUBA), and in particular, to an improved secondary breathing device which can be attached to a SCUBA tank for the purpose of allowing a second diver to safely access the breathable gas, for example air, from the supply of the SCUBA tank in an emergency situation.
2. Description of Related Art
Most SCUBA divers will only dive in pairs, for safety reasons. In an emergency, one diver can often save the life of the other. One of the most obvious and dangerous emergencies is when one of the divers unexpectedly runs out of air. Unless the divers are very close to the surface, the only solution to the emergency is for both divers to share the air of the diver who still has a useable supply. This has been accomplished in the past by the use of various devices and or procedures. The actual time involved in the process is usually very short, being only long enough for the two divers to safely ascend to the surface.
All present systems for supplying a companion diver with air in an emergency are in some way dependant upon the breathing device used by SCUBA divers called a regulator. Most modern regulators consist of two valves connected by a hose, which attaches to a tank of highly compressed air carried by each diver.
One valve, called the first stage, is connected directly to a valve on the tank of air. Its function is to reduce the high pressure of the air coming out of the tank to a safer low pressure. high pressure of the air coming out of the tank to a safer low pressure.
The second valve, at the other end of the hose, is called the second stage. It has a mouthpiece and is held in the mouth of the diver. Its purpose is to deliver the low pressure air in the hose to the mouth of the diver, at ambient pressure, as the diver requires, through normal breathing processes.
One method of sharing air in an emergency is commonly called buddy breathing. It is accomplished by the diver, who is out of air, approaching the other diver, and through the use of hand signals, indicating that he needs air. The two divers then take turns breathing out of the second stage belonging to the diver who still has air. One important problem involved in buddy breathing is its extreme danger if one of the divers panics because of the fear of not getting enough air to breath. This can cause a fight for the single mouthpiece and lead to the death of the weaker of the two divers, or in some cases, both divers. Buddy breathing requires an uncomfortable swimming position, with the two divers facing each other and each with one hand gripping the common second stage. The air loss inherent in this method, as the divers pass the second stage back and forth, is even more dangerous because if one diver has run out of air, it is probable that the other diver is also carrying a tank that is nearing depletion. Yet another danger is that one diver must hold his or her breath while the other diver is breathing. If a diver holds his or her breath while ascending, the resultant lessening of ambient pressure could cause serious internal injury or even death. Finally, sharing a common mouthpiece between divers is also unsanitary. If one diver is aware the other diver has certain medical conditions, that diver may be unwilling to buddy breathe in the first instance. At the same time, a diver aware of his or her own medical condition may be reluctant to seek buddy breathing assistance. Fear of contamination or infection may not seem reasonable to anticipate at first consideration, but it must be remembered that running out of air underwater is as panic prone a situation as can be imagined.
Another, and presently popular method, is the use of a device commonly called an octopus. The octopus is a regulator which has two second stages attached to the first stage instead of just one. Both are identical in every aspect except that the one attached for the emergency use of the dive partner is usually attached to a slightly longer hose to allow the two divers to swim more comfortably side by side while ascending. This is a much safer method. The octopus protects the diver who has run out of air by giving him an additional source of air. The octopus also protects the diver who is carrying it by reducing the possibility that the other diver will panic and attempt to forcibly take the diver's air source out of the diver's mouth. One problem with the octopus is that it is expensive. While the basic regulator, consisting of a first and second stage, is an absolute necessity for SCUBA diving, the added second stage is not. Many divers with a limited budget do not purchase and use the additional second stage on their regulator, hoping that an emergency will not arise, or hoping to be able to handle the emergency by using the buddy breathing method.
Since the second stage device is asymmetrical, with one end attached to a hose, during an emergency in which seconds count and panic is common, it is possible for the diver who needs the air to fumble away precious seconds trying to get the proper part of the second stage in his mouth. During night dives and under cloudy water conditions, it is not always possible to even look at the second stage before trying to use it. It is also dangerous in the situation in which the diver needing the air has already exhaled. The dead space of the extra second stage is large, and is filled with water as it hangs on the extra hose. If the diver without air tries to inhale from a normal second stage, he or she will get a mouthful of water before getting any air, possibly causing choking. The only way to avoid this problem is to press a purge button on the second stage which will blow the water out of the regulator before it is used. This means that the diver experiencing the emergency must have the functional use of at least one hand in order to use the device. More importantly, the diver must also remember to perform this action while the diver is in this emergency situation. Such emergencies do not usually occur, and too many divers do not practice enough.
In the event the diver in trouble is unconscious, or otherwise incapacitated, it may be very difficult or impossible for the rescuing diver to force the large mouthpiece of a normal regulator second stage into the mouth of the diver needing it.
Another problem with the octopus is that the regulator second stage that is hanging on the end of that extra hose for emergency use is left dangling freely from the equipment of the diver. It must be carried that way so the diver who runs cut of air can quickly grab it for emergency use. Unfortunately, the octopus has a shape and size, as it hangs freely, which makes the octopus prone to getting caught in crevices and tangled on submerged fishing lines or any number of other underwater hazards. The octopus therefore poses a danger to the diver to whom it is attached, even absent any emergency. Another problem, related to hanging freely, is that the second mouthpiece is subject to being clogged with sand or mud from the bottom during the course of the dive, without either diver being aware of the octopus being thereby rendered inoperable for any possible emergency. Finally, the octopus will cease to function over time even absent any of the problems noted above, unless it is be carefully maintained, washed after each dive and periodically serviced by trained personnel. Otherwise it will not function.
The kinds of problems described above in connection with SCUBA gear are also problems faces by firemen, and other rescue workers, who upon entering mines, tunnels and similar hostile environments, must also carry self contained breathing apparatus. Rescue breathing equipment is subject to the same dangers as those for SCUBA divers.
Accordingly, there is a long felt need for an auxiliary breathing device which can be safely and conveniently used with SCUBA gear and other rescue breathing apparatus in an emergency and without the problems and additional risks described above.